<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>BFC演示三</title>
    <style>
        .outer {
          width: 400px;
          background-color: green;
          /* 开启BFC解决 */
          /*float: left;*/
          /*position: absolute;*/
          /*display: inline-block;*/
          /*display: table;!* 将元素变为表格元素 *!*/
          /*columns: 1;*/
          /*display: flow-root;*/
        }
        .inner {
          width: 100px;
          height: 100px;
          float: left;
        }
        .inner1 {
          background-color: #01A6DE;
        }
        .inner2 {
          background-color: purple;
        }
    </style>
</head>
<body>
  <div class="outer">
    <div class="inner inner1"></div>
    <div class="inner inner2"></div>
  </div>
</body>
</html>